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1.
Chickpea is one of the major legume crops in the northern parts of Algeria, with 60 000 ha sown. The different viral diseases observed on this crop are partially responsible for the low yields obtained. Of the viruses involved, bean yellow mosaic potyvirus (BYMV), associated with 'narrow-leaf disease, has been identified in the central parts of the country since 1994. The host range was screened and found to include species of Fabaceae, Solanaceae and Cucurbitaceae. Three aphid species ( Acyrthosiphon pisum, Aphis craccivora and Aulacorthum solani ) have been shown to transmit the virus. Two chickpea cultivars (ILC 3279 and ILC 482) carry BYMV in the seed cotyledons. The virus has been purified, antiserum has been produced and electrophoretic analysis has been conducted.  相似文献   

2.
Sugar cane is an important tropical and sub-tropical crop that occupies large areas of land around sugar factories capable of processing 5000 to 15 000 tonnes of cane per day. These areas are usually kept continuously under the same crop, about one-tenth to one-third of the land being ploughed and replanted with sugar cane every year. The major pests of sugar cane are rats, stalk borers, white grubs and froghoppers. Other important pests include root-feeding nematodes, top borers, scale insects, planthoppers and soldier fly. Chemical control is practised to some extent against most of these pests, although biological control is the most common method of combating stalk-borers and has had other notable successes, particularly in Hawaii and Mauritius. Rats are controlled with baits incorporating poisons such as anticoagulants, endrin or zinc phosphide. Aerial applications of insecticide sprays, dusts or granules are used against some stalk-borers (azinphos-methyl), froghoppers (omethoate, propoxur, vamidothion, methidathion, monocrotophos, malathion, carbaryl, gamma-HCH) and plant hoppers (malathion, fenitrothion, endrin). White grubs, soldier fly (crude HCH, dieldrin) and nematodes [1,2-dibromoethane (EDB), 1,2-dibromo-3-chloropropane (DBCP), aldicarb] are usually controlled with soil applications of the appropriate chemicals. The use of chemical control is restricted in some areas because it is too costly and in other areas because of its possibly adverse effects upon the natural or biological control of other pests. Historically, pest control in sugar cane has tended to develop towards a simple integrated system, making use of cultural methods in conjunction with chemicals or exotic parasites and predators. Increasingly, allowance has been made for the contribution of indigenous natural enemies to the prevention of crop losses by a more careful, selective use of insecticides.  相似文献   

3.
Integrated pest management systems were developed originally in response to the appearance of insect populations with resistance to common insecticides. Cotton with its heavy dependence on insecticidal sprays was one of the first crops in which the effectiveness of control declined due to resistance in the target pests. Although insecticide resistance is more of a problem in large scale production systems, the IPM approach can also benefit the smallholder by reducing the number of sprays required with consequent cost savings. Where crop growth is adversely affected by diseases, competition from weeds or poor management, the full benefit of insecticide spray programmes cannot be realised. To be fully effective, insect control should therefore be integrated with other crop protection activities. This paper reviews the insect pests, diseases and weed problems of cotton in Africa and discusses the possibilities for extending the principles of IPM to cover all the crop protection activities with practical examples drawn from both small scale and larger scale production systems.  相似文献   

4.
油菜是临夏州最重要的经济作物,受多种害虫危害,尤其是苗期(子叶~7叶)。本实验在2012年设在甘肃临夏州和政县,选用2种药剂(毒死蜱与辛硫磷)来防治春油菜苗期主要害虫油菜跳蚤甲(Psylliodes punctifrons Baly)。比较了2种农药及2种施药方法对害虫防效的差异,分析防效与产量之间的线性相关性,并从中选择出适宜保苗、保产的农药。对春油菜苗期害虫防治提出了建议,为临夏州春油菜区害虫综合防治提供了一定的理论支撑。  相似文献   

5.
6.
‘De Groene Vlieg’ (the Green Fly) is an independent company offering various services concerning integrated pest management in open field agriculture in the Netherlands. One such service is the supervised control of carrot fly (Psila rosae). From 1993 to 2008 the company has monitored the carrot fly population on a total of nearly 65 000 hectares resulting in an extensive dataset. The data was not collected according to proper experimental methods, hence it is titled dirty, but the size of the dataset does allow valuable insights to be gained. De Groene Vlieg monitors the carrot fly population on each field separately. Sticky traps are collected weekly and flies are counted in the laboratory. Growers receive messages containing advice regarding when to apply insecticides and they are responsible for doing so. Overall, over a third of the fields require no spraying at all and for 75% of the fields growers are advised to spray three times or less. One insight from the dataset is that small carrots require more insecticide treatments than large carrots (‘winter carrots’). Reasons for this difference are probably both regional and cultural. Additionally, focusing on a small and uniform area reveals that carrot fly population dynamics are highly variable between years. Another insight is that sowing date has a large effect on the number of insecticide sprayings that are required. Fields sown before the first flight have more flies in the second flight than fields sown later. Comparison of biological and conventional carrot fields shows that carrot fly populations are similar for the first flight. However, during the second flight the number of flies is much higher on organic fields than on conventional ones. Finally, insecticide seed treatment with chlorfenvinphos to control the reproduction of the first flight appears slightly more efficient than supervised control. However, supervised control seems as efficient as seed treatment with clothianidin and beta cyfluthrin.  相似文献   

7.
Action thresholds as decision tools for insecticide application were developed and tested against the major insect pests of rice at four sites in the Philippines over a 13-year period. Action threshold treatments were compared to the farmers' practice, prophylactic insecticide usage, and an untreated check. Yield loss data using the insecticide check method partitioned yield losses over three crop growth stages in the same test fields. Chronic pests that exceeded action thresholds in 79% of fields were whorl maggot Hydrellia philippina Ferino (Diptera: Ephydridae), defoliators Naranga aenescens Moore and Rivula atimeta (Swinhoe) (Lepidoptera: Noctuidae), leaffolders Cnaphalocrocis medinalis (Guenée) and Marasmia patnalis Bradley (Lepidoptera: Pyralidae), and stemborers Scirpophaga incertulas (Walker) and S. innotata (Walker) (Lepidoptera: Pyralidae). Minor chronic pests reached threshold levels in only one site each: rice bug Leptocorisa oratorius (F.) (Koronadal), whitebacked planthopper Sogatella furcifera (Horvath) (Zaragoza) and green leafhopper Nephotettix virescens (Distant) (Guimba); brown planthopper Nilaparvata lugens (Stål) did not exceed a threshold in any field. Stemborers were the most important pest group in terms of yield loss. Despite the insecticide check method underestimating losses, a mean crop loss of 0.62 t/ha was measured which showed ample scope for corrective action. But loss was evenly distributed across crop growth stages (0.15?–?0.24 t/ha) reducing the impact of insecticides. Action threshold treatments overall outyielded the untreated check, more so in the two sites with highest pest density. The benefit of thresholds was to reduce insecticide usage, as a cost saving. However all the practices showed poor economic returns including the farmers' practice. Farmers' practice employed low insecticide dosages and timing was not consistent with pest damage, but yields were often similar to threshold treatments. Farmers appear to use insecticide more for risk aversion than for profit. The best threshold characters when evaluated against resulting pest density and yield loss criteria showed accuracies >?90% correct decisions. Future work is needed to improve the insecticide response rather than monitoring tools. Thresholds need to be incorporated into improved crop management, which was often found suboptimal by farmers, to take advantage of the high levels of tolerance in modern high tillering cultivars. Crop husbandry practices which improve yield potential such as selection of longer maturing varieties and nitrogen fertilizer may be a more effective pest management strategy than insecticides.  相似文献   

8.
4种种衣剂防治棉花苗期主要病虫害效果及经济效益比较   总被引:1,自引:0,他引:1  
为明确4种复合型种衣剂对棉花苗期主要病虫害的防治效果和经济效益,以‘新陆早41号’为试材,采用田间小区试验,研究400 g/L福美双·萎锈灵种子处理悬浮剂(FS)、26%多菌灵·福美双·甲基立枯磷FS、25%噻虫嗪·咯菌腈·精甲霜灵FS和30%噻虫嗪·嘧菌酯·咪鲜胺FS对棉花出苗、苗期立枯病和红腐病、地下害虫、苗期蓟马、蚜虫和产量的影响,分析其防治病虫害的效果及经济效益,以期筛选出田间试验效果最佳的种衣剂。结果表明:播种10 d时4种种衣剂处理的出苗率显著优于对照,较对照增加6.64%~19.23%,播种30 d时4种种衣剂对苗期立枯病和红腐病防治效果分别为30.88%~50.74%和31.13%~59.15%,对棉花地下害虫和蓟马的防治效果分别为39.24%~69.62%和39.12%~63.04%。棉花上蚜虫发生时间推迟1~3 d。400 g/L福美双·萎锈灵FS防病效果最佳,25%噻虫嗪·咯菌腈·精甲霜灵FS防虫效果最佳。种衣剂处理收获株数较对照增加0.78%~1.11%,增产量为53.70~184.40 kg/hm 2,经济效益为322.20~1106.40元/hm 2,投入产出比为1∶5.65~1∶12.29。综合分析显示,25%噻虫嗪·咯菌腈·精甲霜灵FS防治苗期病虫害和增产效果较好,具有推广应用价值。  相似文献   

9.
在推进现代甘蔗产业过程中,有效防控甘蔗病虫害是"双高"甘蔗栽培技术的一个重要环节。目前世界上已发现的甘蔗病害有120种以上,甘蔗害虫上百种,不同国家、不同蔗区甘蔗病虫害种类不同,病菌生理小种、病毒株系也不相同,而许多重要的甘蔗病虫害都是通过种苗传播的。提高对潜在的检疫性甘蔗有害生物认识,有效地阻止危险性病虫随种苗传播蔓延,增强减灾防灾能力,对确保甘蔗品种质量和甘蔗生产安全,促进甘蔗种植业和蔗糖产业持续稳定健康发展具有重要意义。本文重点介绍了几种潜在的检疫性甘蔗有害生物,并提出了相应的防控对策。  相似文献   

10.
Potato is an important crop for Polish agriculture, now grown on an area of 1.8 million ha, with an annual production of about 35 million t. The crop is used for fodder (pork production), human consumption and as a raw material for various branches of industry. High quantity and quality are essential for proper utilization. The main limiting factors in Polish potato production are: water (shortage or excess), seed potato quality, cultivation practices, and damage by pests, diseases and weeds. Improving the economics of potato production depends on decreasing the acreage and increasing the extent of proper protection. The major constraint is late blight (Phytophthora infestans) which causes yield losses estimated at 22.8%. Blight control is indispensable. The level of resistance among Polish cultivars, both in haulm and tuber, is not satisfactory, so more intensive resistance breeding is needed. Chemical control has increased in popularity, but improper use of phenylamides has created new problems. Further progress will depend on cost-effective methods of control and reliable use of fungicides.  相似文献   

11.

Field experiments were carried out at Samaru, Nigeria in the 1993 and 1994 cropping seasons to investigate the effect of insect pests on the yield of bambara groundnut. There was significant reduction in pod and seed yields of bambara groundnut in both years due to insect pests. The application of a mixture of Karate e.c. at 25 g a.i./ha and dimethoate e.c. at 400 g a.i./ha, respectively, at fortnightly intervals from crop flowering significantly increased pod and seed yields of bambara groundnut, preventing pod losses of 67% and 38% and seed losses of 71% and 43% in 1993 and 1994, respectively.  相似文献   

12.
Abstract

Malathion seed treatments were evaluated as a means of protecting aerially‐sown rice from attack by Chironomus tepperi Skuse and other chironomids in New South Wales, Australia. Four treatments were examined: malathion applied to seed at 150, 300, and 450 ga.i/ha, and malathion applied directly to water at 300 ga.i./ha. Chironominae were significantly suppressed for 10 days by all treatments, but populations were often significantly above control levels at 20 and 25 days post‐treatment. None of the treatments significantly reduced other chironomids(predominantly Tanypodinae) at any stage of the trial. Emergence trap data from control and water treatment bays showed that there was, in practical terms, only a single generation of C. tepperi during crop establishment, and that malathion applied directly to water at 300 ga.i./ha almost completely eliminated adult emergence in this species. Bioassays of field‐collected water samples showed that malathion dissipates readily from seed into the water column. Toxicity profiles over time for the 150 and 300 g a.i./ha seed treatments were statistically similar to that for the 300 ga.i./ha water treatment. Although the 450 ga.i./ha seed treatment provided slightly longer residual toxicity, control was not enhanced sufficiently to justify an increase in the existing application rate of 300 ga.i./ha.  相似文献   

13.
短稳杆菌农药是我国自主创制的一种生物杀虫剂,对小菜蛾、斜纹夜蛾及其他鳞翅目害虫有很好的杀虫效果,对蔬菜本身及害虫天敌无不良影响,对人畜禽安全性好。100亿孢子/mL短稳杆菌悬浮剂用于蔬菜大田害虫防治,应当准确掌握用药对象、用药时期及用药方法。  相似文献   

14.
小麦主要病虫分期混合施药技术   总被引:1,自引:0,他引:1  
研究结果表明,小麦主要病虫的发生有明显的阶段性,秋苗期主要是纹枯病和地下害虫,返青拔节期主要是纹枯病和麦蜘蛛,两者皆在3月25日前后进入侵染和为害盛期;穗期主要有白粉病、叶锈病和麦蚜,有的年份条锈病流行,它们多在5月1日前后进入盛发期。播种期、返青拔节期和穗期3期,杀虫剂与杀菌剂混合施药具有良好的药效和明显的增产作用,特别是穗期。3期混合施药的最优组合是:播种期,0.08%甲基异柳磷与0.03%三唑醇混合拌种,返青拔节期,甲基硫环磷(175.5g/ha)与三唑醇(75g/ha)混合喷雾;穗期,抗蚜威(45g/ha)与三唑醇(105g/ha)混合喷雾。3期施药经济效益显著,投入产出比1: 12.7~14.1,每ha纯收益1450.5~1797.0元。  相似文献   

15.
植保无人飞机低空低容量喷雾技术应用与展望   总被引:8,自引:0,他引:8  
近十年来,我国植保无人飞机迅猛发展,应用的农作物范围越来越广,不仅在水稻、小麦、玉米等主要粮食作物得到了应用,在橡胶、槟榔等高大植株的病虫害防治中更有其独特优势,已经初步形成了我国植保无人飞机低空低容量喷雾的喷头配置、配套药剂、飞防助剂、作业参数等技术体系,对于重要农作物病虫害如稻纵卷叶螟、水稻纹枯病、小麦蚜虫、玉米黏虫等防治效果均在80%以上,在各地病虫害防控中发挥了重要作用。但是,植保无人飞机喷雾作业过程中,还存在炸机或失控、雾滴飘移药害、药液分层结块、防治效果不稳定等问题。通过汇总分析植保无人飞机在重要病虫草害防治工作的成功经验和安全事故,本文提出植保无人飞机低容量喷雾技术将会得到更广泛的应用,植保无人飞机专用药剂和配套助剂、变量施药、多传感器数据融合、多机协同、精准施药、施药标准和规范等都将得到长足的发展,为现代农业和智慧农业发展提供技术支持。  相似文献   

16.
Control of seedling diseases is a major priority in many crop systems. Seed treatments that induce systemic resistance after seedling emergence may be an ideal way to provide protection against disease during the establishment of the crop. CGA 245704, a chemical activator of systemic acquired resistance, was tested as a seed treatment against two Brassica diseases with contrasting infection biologies, the airborne downy mildew pathogen, Peronospora parasitica, and the soilborne fungus, Rhizoctonia solani. Seeds of two Brassica spp. were either imbibed with various concentrations of the compound or imbibed and then dried. Both the imbibition treatment alone and the imbibition treatment followed by seed drying had a significant effect on the sporulation intensity of P. parasitica for all concentrations of the compound used, whereas the imbibition treatment provided some control of damping-off caused by R. solani, with the degree of control being highly dependent on the concentration applied to the seed. Seed treatment with the plant activator CGA 245704 might therefore simultaneously control several seedling diseases, thereby providing a novel option for management of these diseases. © 1998 SCI.  相似文献   

17.
Cereal cyst nematode is a major pathogen in southern Australia costing $40 to $80 million in lost production each year. Our research has shown that three chemicals applied with the seed in the drill row, viz. Counter (terbufos) granules, Vydate (oxamyl) as a seed dressing and Nemadi (ethylene dibromide), reduced Heterodera avenae damage and gave yield increases which are economical in the Australian wheat farming system. A plant assay of soil has been developed to assess potential damage by H. avenae before employing chemical control. Wheat yields 2 years after growing H. avenae-resistant Festiguay wheat were 0.4 to 1 t/ha higher than after other cultivars. Rotations with legumes alternating with wheat reduced damage from H. avenae. Wheat sown without cultivation (minimum tillage) resulted in less root damage from H. avenae and higher yields than when sown into cultivated soil.  相似文献   

18.
B. J. WILSON 《Weed Research》1985,25(3):213-219
Avena fatua was sown in a cultivation experiment in the autumn of 3 successive years. For each population seedling emergence and viable seeds in the soil were recorded for 4 years in crops of winter barley in which new seed production was prevented. About half of the seeds sown were recovered after 1 year. In subsequent years viable seeds in the soil declined more rapidly with tine cultivation than with ploughing. After 4 years up to 5% of the original seeds were still viable. One population exhibited greater seed dormancy than the other two populations, due it is thought to higher summer rainfall and the greater availability of moisture during seed maturation. Most seedlings emerged in the autumn and spring, between 12 and 18 months after sowing. A total of 950 seedlings emerged from 12 000 seeds sown; 21% of these seedlings came from new seeds (< 1 year old), 57% from seeds 1–2 years old, 14% from seeds 2–3 years old and 8% from seeds 3–4 years old. Autumn seedlings arose fairly evenly from all age groups while spring seedlings mostly came from the 1–2-year-old seeds. With tine cultivation total seedlings over 4 years represented 9–7% and with ploughing 6–2% of the original seeds sown. A. fatua was more persistent than in previous experiments in spring barley, which suggests that control measures would have to be applied for longer in a succession of winter cereals than spring-sown crops to reduce A. fatua to low populations.  相似文献   

19.
BACKGROUND: Cruciferous oil-bearing crops have gained in importance worldwide. The expansion of the growing area of these crops has caused a proliferation of pests. Exposure to organophosphate, carbamate and pyrethroid insecticides has been associated with bee poisoning in food crops. This study examines the repellent effect of alpha-cypermethrin on the number of foraging honey bees, Apis mellifera L., on fields of spring oilseed rape, Brassica napus L. var. oleifera. RESULTS: The first experiment was conducted on differently sprayed 10 m(2) experimental plots where alpha-cypermethrin was applied at different times. Another experiment was conducted on a 4 ha seed production field divided into two parts: one part was treated with alpha-cypermethrin and the other was not treated with this insecticide. The results show that there was no difference in the number of honey bees between alpha-cypermethrin-treated and untreated patches. The result persisted through three observation years, regardless of varying flower and honey bee densities. CONCLUSION: No repellent effect of the insecticide on honey bees was found even 24 h after spraying. The density of oilseed rape flowers most likely played a major role in choosing the foraging area.  相似文献   

20.
1981—1984年广东省开展甘蔗害虫综合防治研究、试验、示范。采取“以农业防治为基础,释放赤眼蜂防治蔗螟;科学用药,保护天敌,充分发挥天敌自然控制多种害虫的作用”。在10万亩大面积上,收到到了显著的经济效益、生态效益和环境保护效益。  相似文献   

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